The subject of the article is an attempt to answer the question about the possibility to present the existence as the category that is in the base of the reasoning about being. In the first place, the author points out that this concept in ancient thought was not the category underlying the philosophical deliberations. This function performed the term το οѵ (something) expressing what we traditionally associate with the notion of being. Existence is a category that appears in philosophy through the ideas of religious Judaism taken over by Christianity and Islam and by Arab philosophy. It has become the subject of philosophical analyzes in European thought due to the philosophy of St. Thomas Aquinas, as well as twentieth-century neotomism and as a category of being in M. Heidegger’s philosophy. According to the author of the text, existence in experience is presented by the multiplicity and variety of moments, and in the order of thinking is understood as one (whole), and thus as something (being).